webhook is a lightweight configurable tool written in Go, that allows you to
easily create HTTP endpoints (hooks) on your server, which you can use to
execute configured commands. You can also pass data from the HTTP request
(such as headers, payload or query variables) to your commands. webhook also
allows you to specify rules which have to be satisfied in order for the hook
to be triggered.

For example, if you're using Github or Bitbucket, you can use webhook to set
up a hook that runs a redeploy script for your project on your staging server,
whenever you push changes to the master branch of your project.

If you use Mattermost or Slack, you can set up an "Outgoing webhook
integration" or "Slash command" to run various commands on your server, which
can then report back directly to you or your channels using the "Incoming
webhook integrations", or the appropriate response body.

webhook aims to do nothing more than it should do, and that is:
1. receive the request,
2. parse the headers, payload and query variables,
3. check if the specified rules for the hook are satisfied,
4. and finally, pass the specified arguments to the specified command via
   command line arguments or via environment variables.

Everything else is the responsibility of the command's author.
